Aisling Bea has hailed the strong bond she has with her This Way Up co-star Sharon Horgan, saying "we are very like sisters, to be fair".
The actors play on-screen sisters in the Bafta-winning Channel 4 comedy, which was written by Bea, and the Kildare comedian said they have a natural chemistry that comes from their closeness.
Speaking on The Ryan Tubridy Show on RTÉ Radio 1, Bea shared: "We are very like sisters, to be fair.
"Sharon is like family and I'm quite close to her family as well... we do have that very sisterly relationship."
The hit comedy about sisters Áine (Bea) and Shona (Horgan) first aired in 2019 and has now returned for a second run.
Bea said she has been "overwhelmed" by the positive reaction to the new series, which felt gratifying, as the show had been difficult to produce during the pandemic.
"That's been really nice because it's been a bit of a slog getting things made in the last year-and-a-half," she told host Tubridy.
The 37-year-old writer and actress wrote the first season of This Way Up after a show she had created with Horgan was cancelled by Channel 4, which decided to commission Derry Girls instead.
Bea explained: "I was like, 'Derry Girls, what's that?' That turned out to be one of my favourite comedies in the world, I think we'll all agree.
"This was a second inning of me trying to write something for myself and Sharon to stay sisters. That chemistry is there and I think we found that bond 12 or 13 years ago when we first met playing sisters on a show she wrote called Dead Boss.
"I think when you find that spark you want to foster it creatively because doing any kind of artistic thing can be tough work. But when you find something that feels like sliding along in oil, you're like, 'Oh, I better hold onto that, so. That's very freeflow'.
"When we're acting out our scenes it doesn't take very long. We spit them out quite quickly because it's sort of our rhythm."
When Tubridy commented on the Irishness of This Way Up, Bea agreed that specific references were important to her writing.
"I think specificity works really well. The rule of thumb is if you're talking about your nightclub in your hometown, someone in Alaska will remember their hometown," she explained.
"And if you show the smallness of your relationship with your sister, like an in-joke that an audience might not technically get, they'll know an in-joke that they have with their brother or sister.
"When you go too broad it appeals to no one, in a sense. So, the more specific you are about a detail, people will actually connect more to that."